Note: Descriptions are shown in the official language in which they were submitted.
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COM~OSIT~ CONTAIN~RS
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~CHNICAL ~IELD
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This invention relates to containers of the
kind co~only known as composite containers, that is to
say a container having a body comprising a shell ~f
paperboard material (as hereinafter defined), and a base
member sealably closing the bottom end of the shell.
The invention is however concerned with composite
containers of the particular kind which each has a removable
closure, the body having Q protective metal ring isecured
fast over the top end of the shell to define an open
mouth of the container body and the closure being
insertable into tight sealing engagement ~ith the ring.
~he term "paperboard" is to be understood to
mean any material consisting who]ly or partly of
paperboard, cardboard or the like, ~hether or not the
material o~ the shell includes also one or more other
materials, for example metal foil or plastics, applied
as R la~er to one OI' both surfaces of the paperboard or
otherwise incorporated in the material.
~ACKGROUND AR~
Composite containers whose body shells are at
least partially formed from paperboard are well known7
Such containers commonly comprise a plurality of layers
of material spirally or convolutely wound one upon the
other to provide a generally cylindrical cardboard body
whose interior is lined with metal foil or other
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protective me~teria].. During manufacture, the layers of
material are continuously wound to produce a tube from
which the body shells are severed.
'l'o close -the body of such R container it has
been proposed to secure a base over one end and slidably
to insert into the other end a removable closure~
Ho~ever, disadvantages of this arran~ement are :~irstly
that the severing operation to produce each body tends
to give rise to slivers of cardboard which may be
dislodged into the contents of the container by
repeated removal and insertion of the closure; and
secondly the closure tends to damage the foil lining of
the body du.ring insertion. O-ther problems which may
occur with this type of container wherein the closure is
a sliding fit in the container body are leakage of the
cont;ents of the container, and (more importan-tly in some
applications) passage of air into, and gas out o~, the
body which may impair the stora~e life of the contents
of the container.
One object of this invention is to provide a
composite container of the particular kind described
above, wherein such disadvantages a.re avoided and which
is of a construction suitable for use as a large sealed
container for heavy products, such as paint, as well as
for manu~acture in smaller sizes ~or any flowable
product that requires to be kept in a sealed condition.
Such products may include dry or liquid or semi-liquid
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foodstuffs.
DI,SCLOSUR~ OF INVEN~ION
~ he invention accordingly provides a
container of the particular kind described above in
which the protectlve metal rin~ has an inner skirt
which comprises a wall portion in the ~eneral shape of
a frustum of a cone, this wall portion terminating in a
curl portion which is of relative]y large diameter and
substantially toroidal in shape. '~he curl lies
radially inward of the frusto-conical wall portion and
has a concealed terminal edge as An important safety
feature, this edge fflcing generally radially-outwardly
and downwardly. The removable closure has means which
en~age behind the curl so that the closure makes a
close snap fit in the protective ring. ~he resilience
necessary to es-tablish a snap flt is provided either by
the closure or by the inner skir-t of the ring, or by
both; but both the closure and the inner skirt are
sufficiently stiff to have only this resilience, thus
providin~ a close seal between the closure and the
container body.
Another important feature of the invention is
that in the outer wall portion of the ring, which fits
closely arou~d an upper terminal portion of the
cylindrical body shell and terminates in a flange, this
flange is directed inwardly and upwardly and is spaced
radially from the ou-ter wall portion of the rin~. In
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-this way the ring is given some re~silience whereby the
flange which bites into the outer surface of the
material of the shell to secure the ring intimately to
the latter, is enabled to exert a positive radial force
5 into the shell material.
BRIE~ D~SCRIPTION 0~ DRAWqNG~
One e~bodiment of the invention will now be
described, by way of example only, with reference to
the drawings of this Application, ~herein:-
Figure 1 is an upright, diametral section
through a container embodying the invention, and
~ igure 2 is an enlarged fragmentary sectionshowing a detail of the container.
E~ MODE OF CARRYING OUT THE II~EN~'ION
Figures 1 and 2 illustrate A container 10
whose body comprises a cylindrical shell 12 formed from
spirally ~,ound layers of cardbo~lrd and foil, the
cardboard lying outside the foilO l`he body 12
includes a base member 14 sealably closing the bottom
end of th~ shell. An end portion 13 of the shell 12
terminates in a rim 16 encircling an open mouth 18 of
the container body.
`Closely fitted over the ri~ 16 is a protective
ring 20 (see ~igure 2) formed from sheet metal. This
ring 20 has an outer wall portion 22 which lies ~losely
against an outer surface 24 of the body end portion 13
and which has an inturned flange 26, directed inwardly
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and upwardly and spaced from the outer ~-all portion 22.
An inner skirt 28 of the ring 20 comprisès an inner
all portion 29 and a generally-toroidal curl portion 30
gradually curving inwardly from an inner surface 32
of the body shell 129 then generally towards the rim 16,
and finally downwardly away from the rim 16 and back
towards the surface 32 (as shown in ~igure 2) so that
a terminal edge 34 of the curl portion 30 faces
generally outwardl~ and downwardly and is thereby
concealed. Injury to handlers of the container may
-thus be avoided. ~he inner skirt 28 lies a~ainst the
inner surface 32 adjacent to the rim 16~ but is frusto-
conical in shape, converging downwardly and becomin~
thus s~aced from the inner surface ~2 of the body shell
toward the curl portion 30, which, by virtue of its
curved contour provides a radially-inwardly projecting
ridge.
~ he curl portion 30 is of relativel~ large
diame-ter, and its terminal edge 34 is ~referably spaced
slightly, as seen in Fib~re 2, from the adjacent inner
wall portion 29.
During manufacture of the container body, the
inner skirt 28 of the ring 20 is inserted into the
container mouth 18, the remainder of the ring,
comprising an outer portion 1i7, being at this time
sli~htly curled from the rim 16 towards the outer
surface 24 of the shell 12~ (not shown).
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The terminal edge 36 of the ring
is then forced inwardly so as to bite into surface 24
and to~rards the rim 16, creating a groove 25 in the
surface 24. ~he outer portion 17 is also forced
generall~ towards the surface 24 until the outer
portion 17 lies closely against the surface 24 and the
in-turned flange 26 i~s formed. As seen in Figure 2,
the flange 26 thus bites into the surface 24, bearing
radially against the groove 25 and thus positively
retaining the ring 20 on the end portion 13 of the
shell.
In addition to the container body, the
container 10 con)prises a removable plug closure 38
fo~med from a resilient plastics material. The
closure 38 is hollo~- and has an enlarged end 40
providing a shoulder 42, behind which the ridge formed
by the curl portion 30 of the ring 20 is engageable to
hold the closure 38 in the ring. A radially outwardly-
directed flange 44 is also provided on the closure 38
to abut the rim 16 and thereby prevent the closure from
bein~ forced too far into the container body.
As the closure 38 is inserted into the
body 12, the enlarged end 40 is resiliently deformed to
allow the closure to fit through the ring 20. The
closure 38 then snaps into position, closing the mouth 18,
the enl~rged end 40 returning to its original condition
and the edge region 30 of the ring 20 engaging behind
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the shoulder 42. The shape of the inner skirt 28 is
such that it exerts a positive radial force on the
closure, there being only sufficient resilience in the
closure and in the skirt 28 to permit insertion and
removal of the closure~ Consequently the inner skirt
and closure together constitute a space structure of
considerable mechanical strength, by virtue of the
opposed radial forces exerted by the skirt and the
closure upon each other. ~he closure 38 is thus
positively retained in the mouth 18, a seal being
effected between the ring 20 and the closure 3~ to
inhibit leakage of the container's contents and the
passage of gas between the interior of the container
and the ambient atmosphere. As illustrated, the
contour of the shoulder 42 is arran~ed to conform to
that of the ed~e region 30, so that an area of contact,
rather than a line of contact, is achieved between the
two which enhsnces the sealing effect achieved by the
snap fit arrangement of this invention.
~0 In an alternative construction, the closure
hss a circumferentially extending rib in place of the
enlarged end 40 to provide a shoulder behind which the
curl portion 30 is engageable.
